For oil changes, I normally just jack up the front driver's side corner of the car. It provides plenty of clearance for an oil drain pan.

Locate the factory jack point. On E30s, it is just behind the front quarter panel along the bottom edge of the rocker panel.

Use a hydraulic jack (or your factory jack) to lift the driver's side of the car.

Be sure that the jack pad stays firmly planted in the jack point as you lift the car. The pad on my jack has a nice little tab that fits up into the hole in the middle of the jack point to help keep it secure.